1066636691 has 2 divisors, whose sum is σ = 1066636692. Its totient is φ = 1066636690.

The previous prime is 1066636663. The next prime is 1066636709. The reversal of 1066636691 is 1966366601.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1066636691 is a prime.

It is a super-2 number, since 2×1066636691² = 2275427661174858962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1066636601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 533318345 + 533318346.

It is an arithmetic number, because the mean of its divisors is an integer number (533318346).

Almost surely, 2^1066636691 is an apocalyptic number.

1066636691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1066636691 is an equidigital number, since it uses as much as digits as its factorization.

1066636691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 44.

The square root of 1066636691 is about 32659.4043270847. The cubic root of 1066636691 is about 1021.7363386700.

The spelling of 1066636691 in words is "one billion, sixty-six million, six hundred thirty-six thousand, six hundred ninety-one".